Ventilation system and method for automotive lighting systems

ABSTRACT

A ventilation system and method for automotive lighting systems includes at least two tortuous paths between the interior of the lighting enclosure and the surrounding atmosphere. The two paths include portions which are at least partially vertical and gravity assists in separating foreign material from air drawn through these portions. By providing at least two paths, foreign material in one path will not be drawn into the enclosure as air can still pass through the other path. The ventilation system and method can be integrally formed with the enclosure, or can be separately formed and attached to the enclosure.

FIELD OF THE INVENTION

The present invention relates to a system and method for ventilatingenclosures. More specifically, the present invention relates to a systemand method of ventilating an automotive lighting enclosure.

BACKGROUND OF THE INVENTION

Automotive lighting enclosures typically are heated by the light sourcesthey enclose. The air in the light enclosure expands when heated by theoperation of the light sources and contracts when cooled to ambienttemperature by the deactivation of the light sources. The amount ofexpansion and contraction can be significant and, unless the enclosureis vented, can result in an unsafe overpressure condition in theenclosure. Such an overpressure condition could cause serious injuryshould the enclosure shatter or break in a collision or because of theoverpressure condition.

Accordingly, automotive lighting enclosures are typically vented to theatmosphere to provide pressure relief for expanding and/or contractinggases within the enclosure. However, as automotive lighting systemstypically include reflectors, lenses and/or other optical components andvarious electrical components, it is desired to prevent the ingress offoreign materials, and particularly water, into the enclosure throughthe vent.

To date, automotive lighting enclosures have typically been providedwith vents equipped with filters to prevent the ingress of foreignmaterials. Most commonly, these filters comprise a sheet of a suitablefilter material, such as Goretex™ or a foam, which is affixed over thevent exit.

While such filter-based vents have worked, they do suffer fromdisadvantages in that the filter must be installed in a separatemanufacturing step and the filter material can degrade over time and/oris expensive to purchase.

Other approaches have been to provide a convoluted vent path throughwhich atmosphere can exit and enter the lighting enclosure without theheed for a filter. Ideally, the convoluted path includes one or moreturns which utilize gravity to inhibit rain or other sprayed water fromentering the lighting enclosure through the vent path. However, suchsystems are often less than satisfactory as water droplets or othermaterials in the convoluted path can still be drawn into the lightingenclosure by the decreased pressure in the enclosure when the enclosurecools after use. This decreased pressure acts as a vacuum, relative tothe atmospheric pressure surrounding the enclosure, and will draw inwater or other foreign materials on the convoluted path.

It is desired to have a ventilation system and method for automotivelighting systems which does not suffer from such disadvantages.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a novel ventilationsystem and method for automotive lighting systems which obviates ormitigates at least one disadvantage of the prior art.

According to the present invention, there is provided a lightingenclosure having: a body; a lens, the lens being bonded to the body; avent on the body, the vent including at least two closed tortuous paths,each tortuous path extending between a passage through the body and atleast one respective port exposed to the atmosphere outside the body,each tortuous path including a portion over which foreign material isseparated by gravity from atmosphere moving into the enclosure and eachtortuous path providing a path independent of the other path between theatmosphere and the vent passage to allow atmosphere to enter and exitthe enclosure.

Preferably, each tortuous path is formed between upstanding ribs, thebody of the enclosure and a cover plate. In one embodiment, theupstanding ribs are integrally formed on the body and the cover plate isaffixed to the ribs. In another embodiment, the upstanding ribs areintegrally formed on the cover plate and the ribs are affixed to thebody.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 shows an automotive lighting enclosure with a vent in accordancewith the present invention;

FIG. 2 shows a section, taken along line 2-2 of FIG. 1, of a vent;

FIG. 3 shows a perspective view of another embodiment of a vent inaccordance with the present invention;

FIG. 4 shows a perspective view of another embodiment of a vent inaccordance with the present invention; and

FIG. 5 shows a cross section of the vent of FIG. 4, taken on line 5-5,when installed on a lighting enclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

An automotive lighting enclosure with a vent in accordance with thepresent invention is indicated generally at 20 in FIG. 1. Enclosure 20includes a body 24, a lens 28 and an aperture 32 to receive a lightsource (not shown). Body 24 can also hold at least one reflector (notshown) and one or more lenses (also not shown) if required by the lightsource.

To prevent the ingress of foreign material into enclosure 20, lens 28 isbonded to body 24 such that the joint between body 24 and lens 28 issubstantially air and water tight. To allow for the expansion andcontraction of the air within enclosure 20, a vent 36 in accordance withthe present invention, is included on body 24 as illustrated.

As can be best seen in FIGS. 2 and 3, vent 36 includes a vent passage 40through body 24 and through which the interior of enclosure 20 cancommunicate with the surrounding atmosphere, allowing air to exit and/orenter enclosure 20.

To prevent the ingress of foreign material, such as water, to theinterior of enclosure 20, vent 36 defines two tortuous paths 44 and 48(indicated by the different hatching patterns in FIG. 2) from ventpassage 40. Path 44 interconnects vent passage 40 to two ports 52 and 56and path 48 interconnects vent passage 40 to two ports 60 and 64.

Air from within enclosure 20 can exit the enclosure through vent passage40 and through either or both of paths 44 and 48, ultimately exitingenclosure 20 through one or more of ports 52, 56, 60 and 64. Similarly,air can enter enclosure 20 from the surrounding atmosphere via one ormore of ports 52, 56, 60 and 64 and then via one or both of paths 44 and48 to vent passage 40 and then into the interior of enclosure 20.

Each tortuous path 44 and 48 includes path portions which are orientatedat least partially vertically, such that gravity assists in separatingwater or other foreign materials from air moving through the paths.Water or other foreign material entering ports 52 or 60 will move downand exit ports 56 or 64 under the impetuous of gravity. Water or otherforeign material entering ports 56 or 64 will not be drawn towards ventpassage 40 as air will instead enter through ports 52 or 60.

As should now be apparent, the provision of two separate paths 44 and 48between the respective ones of ports 52, 56, 60 and 64 and vent passage40 prevents the ingress of foreign material, and in particular water,into enclosure 20. Specifically, and unlike prior art systems with aconvoluted path, by providing two separate paths 44 and 48 between ventpassage 40 and ports 52, 56, 60 and 64, if water or other foreignmaterial blocks one of paths 44 or 48, air can still travel into or outof enclosure 20 through the other of paths 44 and 48.

As will be apparent, unlike prior art convoluted path solutions, areduced pressure within enclosure 20 will not result in foreign materialin either path 44 or 48 being “vacuumed” into enclosure 20 as air willinstead be drawn through either path 44 or 48 without the foreignmaterial. This is much different than prior art enclosures withconvoluted path vents where, if a water droplet or other foreignmaterial was in the path, the water or foreign material could bevacuumed into the enclosure as air was drawn into the enclosure throughthe convoluted path.

Vent 36 can be molded in place, as illustrated in FIG. 1, as part ofbody 24, and a cover plate 68 sealed over the face of vent 36. In thiscase, vent 36 is formed from a set of upstanding ribs 72 on body 24 andvent passage 40 is formed through body 24. Cover plate 68 is thensonically or thermally welded or glued, etc. to ribs 72 to form vent 36.

It is also contemplated that vent 36 can be fabricated as a separateunit, as shown in FIG. 3, and welded or otherwise bonded to lightingenclosure 20 With vent passage 40 aligned with an aperture into theinterior of enclosure 20 and cover plate 68 attached.

It is also contemplated that vent 36 can be fabricated as a separateunit with cover plate 68 in place, as shown in FIGS. 4 and 5, andattached to body 24. In this case, ribs 72 are bonded to complementaryrecesses formed in body 24 with vent portion 76 aligned with an aperture204 formed through body 24.

While each of the embodiments discussed above only include two tortuouspaths 44 and 48, the present invention is not so limited and vents 36can include three or more paths, if desired. However, it is contemplatedthat in many circumstances two paths will be sufficient. Further, whileeach of the embodiments described above preferably includes at least twoports for each path, the present invention is not so limited and can beemployed with a single port per path, or with more than two ports perpath, if desired.

The present invention provides a ventilation system and method forautomotive lighting systems and includes at least two tortuous pathsbetween the interior of the lighting enclosure and the surroundingatmosphere. The two paths include portions which are oriented at leastpartially vertically and gravity assists in separating foreign materialfrom air drawn through these portions. By providing at least two paths,foreign material in one path will not be drawn into the enclosure as aircan still pass through the other path. The ventilation system and methodcan be integrally formed with the enclosure, or can be separately formedand attached to the enclosure.

The description of the invention is merely exemplary in nature and,thus, variations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

1. A lighting enclosure comprising: a body; a lens, the lens beingbonded to the body; a vent on the body, the vent including at least twoclosed tortuous paths, each tortuous path extending between a passagethrough the body and at least one respective port exposed to theatmosphere outside the body, each tortuous path including a portion overwhich foreign material is separated by gravity from atmosphere movinginto the enclosure and each tortuous path providing a path independentof the other path between the atmosphere and the vent passage to allowatmosphere to enter and exit the enclosure
 2. A lighting enclosureaccording to claim 1 wherein each tortuous path is formed betweenupstanding ribs, the body of the enclosure and a cover plate.
 3. Alighting enclosure according to claim 2 wherein the upstanding ribs areintegrally formed on the body and the cover plate is affixed to theribs.
 4. A lighting enclosure according to claim 2 wherein theupstanding ribs are integrally formed on the cover plate and the ribsare affixed to the body.
 5. A lighting enclosure according to claim 1wherein each of the at least two tortuous paths terminates in at leasttwo ports in communication with the atmosphere.
 6. A vent for allowingatmosphere in enter and exit a lighting enclosure while inhibiting theingress of foreign material into the enclosure, the vent comprising: avent passage in communication with the interior of the enclosure; atleast two ports, each port in communication with the atmosphere outsidethe enclosure; and at least two tortuous paths to allow atmosphere tomove between the vent passage and at least one of the at least twoports, each respective tortuous path being enclosed and extendingbetween the vent passage and a respective one of the at least two portsand wherein each of the tortuous paths includes at least a portion ofthe path arranged in a substantially vertical manner to encourage theseparation by gravity of foreign material from the atmosphere movingthrough the respective tortuous path to the vent passage.
 7. The ventaccording to claim 6 wherein the at least two tortuous paths are formedbetween ribs upstanding from the body of the enclosure and a coverplate.
 8. The vent according to claim 6 wherein the at least twotortuous paths are formed between the body of the enclosure and ribsupstanding from a cover plate.
 9. The vent according to claim 7 whereinthe ribs are integrally formed with the body and the cover plate isaffixed to the ribs.
 10. The vent according to claim 8 wherein the ribsare integrally formed with the cover plate and the ribs are affixed tothe enclosure.
 11. A method for preventing the ingress and egress offoreign material into a lighting enclosure, comprising: providing a bodyhaving a passage; providing a lens sealed to the body; providing a ventoperably associated with the passage of the body, the vent having atleast two or more ports, and at least two or more tortuous pathsconnecting the passage of the body and the at least two or more ports,and a covet plate; communicating the body and the atmosphere through theuse of the passage, the at least two or more tortuous paths, and the atleast two or more ports; forming the at least two or more tortuous pathsthrough upstanding ribs integrally formed in the vent; and separatingforeign material in the atmosphere communicating from the at least twoor more ports and the body through the use of the at least two or moretortuous paths.
 12. The method of claim 11, wherein each the at leasttwo or more tortuous paths are independent of each other.
 13. The methodof claim 11, further comprising the step of integrally forming theupstanding ribs on the body, and affixing the cover plate to the ribs.14. The method of claim 11, further comprising the step of integrallyforming the upstanding ribs on the cover plate, and affixing theupstanding ribs to the body.
 15. The method of claim 11, furthercomprising the step of gravity separating foreign material from theatmosphere in the one or more tortuous paths.